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Sunday, March 19, 2017

Malaria Mosquitos Really Do Hunt Humans - Science

Maybe you think it's obvious that malaria mosquitos hunt humans since they spread so much of that disease to us but I mean they really hunt us. That species of mosquito has a second set of odor receptors which are tuned specifically to sniffing out humans.

- Insert lengthy editorial on ineffectual attempts to control terrorists which are matched by ineffectual attempts to control mosquitos and we wind up with lots of dead people but not much of an answer -

- Insert lengthy editorial on efforts in Florida to block attempts at mosquito control which would have come through the use of GMO mosquitos ... and the Zika beat goes on -

These researchers are looking for an answer. If we can discover what attracts mosquitos to humans then maybe we can turn it off.

This scanning electron microscope image of the head of a female Anopheles mosquito shows the antennae, proboscis and palps that contain its olfactory systemCredit: Zwiebel Lab, Vanderbilt University

The picture may seem like gratuitous weird but these are the tools by which the mosquito finds us. The eyes look unusual but they're really not good for much whereas they're spectacularly good at differentiating scents.

Biologists who study the malaria mosquito's 'nose' have found that it contains a secondary set of odor sensors that seem to be specially tuned to detect humans. The discovery could aid efforts to figure out how the insects target humans and develop a preference for them.

- SD

It's not stated but discovering how this preference exists makes for the potential to whack it so they stop doing it.

Note: although possibly we could kill all mosquitos, we can't screw with an ecosystem like that since they also fertilize flowers, etc. It's similar with spiders since they also give me the willies but I read a few days ago how spiders in the world eat twice their weight in insects as compared to all humans eat. That makes them some life-saving li'l eight-leggers so I may have to review my position on them somewhat. (Ithaka: Spiders Are Your Friends - Science)

This is how malaria mosquitos can find us.

The scientists think they now have a handle on at least one of the reasons for this disparity. In a paper published earlier this year in the journal Scientific Reports they report that the malaria mosquito has a second complete system of odor sensors -- discovered five years ago in the fruit fly (Drosphila melanogaster) -- that are specially tuned to at least two human-derived chemical signals, which the insect's OR system cannot detect. So adult females use this second system of odor sensors to seek human prey."This appears to be a more primitive olfactory system and one which Anopheles uses to detect humans," said Cornelius Vanderbilt Professor of Biological Sciences Laurence Zwiebel, who directed the study. "It fills important gaps in the mosquito's chemosensory perception that are not provided by the OR system."

- SD

Note: the OR system is the Olfactory Reception system.

There's no miracle punchline at the end of this since research continues.

"The mosquito is an extremely sophisticated organism," said Pitts. "They use a combination of finely tuned olfactory systems to locate their prey. We have now found two of these systems, but, based on what we know about the mosquito's genome, we think there are others that we haven't identified yet.""Despite all the research we have done, we still haven't fully figured out how mosquitoes identify and, even more importantly, develop a preference for humans," Zwiebel observed.

- SD

As you see by the current research, they're searching hard for the reasons. Once they do identify the basis then they should be able to come up with some effective measures to counter it but make no mistake of the importance. Terrorists make the headlines but mosquitos kill far, far more of us.